1. Field of the Invention
The present invention relates to a coil-type electronic component, and more specifically to a coil-type electronic component using a soft magnetic alloy, suitable for a compact coil-type electronic component that can be surface-mounted on a circuit board.
2. Description of the Related Art
Magnetic cores of choke coils used in high-frequency applications are traditionally ferrite cores, cores cut from thin metal sheets, and powder-compressed magnetic cores.
Use of metal magnetic materials has an advantage over ferrites, as these materials can achieve high saturated magnetic flux densities. However, metal magnetic materials are poor in insulation property and must be given insulation treatment.
Patent Literature 1 proposes mixing a Fe—Al—Si powder having surface oxide film with a binder, compression-molding the mixture, and then heat-treating the molded product in an oxidizing ambience. According to the patent literature, heat-treating the molded product in an oxidizing ambience has the effect of forming an oxide layer (alumina) in those areas of the insulation layer on the surface of the alloy powder that have broken during compression molding, thereby achieving a complex magnetic material offering good direct-current superimposition characteristics with minimal core loss.
Patent Literature 2 describes laminating a metal magnetic layer formed by a metal magnetic paste which contains metal magnetic grains as the main ingredient, and also glass, with a conductive pattern formed by a conductive paste containing silver or other metal, and then baking the obtained laminated electronic component, which has the coil pattern formed in the laminate, at a temperature of 400° C. or above in a nitrogen ambience.